Year	constant 2015 US$
1990	382300000
1991	740650000
1992	1018420000
1993	719180000
1994	609130000
1995	717240000
1996	739260000
1997	2239520000
1998	2407720000
1999	2262980000
2000	3296600000
2001	2148800000
2002	2906440000
2003	1968950000
2004	2373020000